Selected nucleosides for measurement of cancer marker and detection of newly synthesized DNA and RNA.

Marker nucleosides such as 1-Methyl-adenosine, 5-Methyl-uridine, N3-methyl-uridine and Pseudouridine are found to be
elevated in assocation with cancer[1], [2], [3]. Jena Bioscience offers proper nucleoside standards for their measurement.

Detection of de novo DNA synthesis or S-Phase synthesis is perfomed with modified nucleosides which are efficiently incorporated into proliferating cells and labeled subsequently. Br-dU can be tagged with the corresponding antibody [4], [5], [6]. 5-EdU will make the newly synthesized DNA visible when cells are incubated subsequently with a fluorescent azide, which is rapidly "click"-coupled to the alkyne group of 5-EdU. In contrast to Br-dU, the method does not require sample fixation or DNA
denaturation and permits good structural preservation [7], [8]. Analog 5-Ethynyl-2'-deoxy-cytidine can be used to detect DNA
synthesis with similar sensitivity as EdU [10].

Based on the same principle, 5-EU can be used for detection of RNA transcription and turnover in vivo. As it is incorporated into RNA transcripts, 5-EU-labeled cellular RNA can be detected quickly and with high sensitivity with fluorescent azides [9].